Section 157(4) in The Gujarat Municipalities Act, 1963
(4)No person shall occupy or permit to be occupied any such building, or use or permit to be used the building or part thereof affected by such work, until(a)the permission referred to in clause (b) of sub-section (3) has been received, or(b)the Chief Officer has failed for one month after the receipt of the notice of completion to intimate as aforesaid his refusal of the said permission.